The Biology of Starvation

Most patients remember one specific event as the initial trigger for their eating disorder. For people who get well in the first few months, the story of the illness stops there. But after even just six months of taking over someone's life, the eating disorder often takes a different course. What started the disease is very different from what lets it continue and worsen over time. In the end the factors that perpetuate the eating disorder easily overshadow the initial event. And one central but easily ignored factor is chronic starvation itself.

Most treatment for eating disorders focuses on both the need to maintain a meal plan and the psychological/emotional issues. However, treatment teams typically separate the duties. The therapist ignores food to focus on the underlying concerns. The nutritionist handles the meal plan. And the primary doctor monitors medical stability. This approach may be thorough, but no one considers all aspects of the illness and thus can't see the entire picture. Without piecing together the psychological and physical, no clinician has a birds eye view of the treatment. No one considers the biological results of starvation.

The doctor would be the team member most likely to recognize this problem, but it's no surprise doctors can't see it either. The Western medical community knows little about chronic starvation. Although many people in this country go hungry, few truly starve. Chronic malnutrition isn't a regular occurrence in the first world. It only occurs in severe, terminal medical illness such as cancer or dementia, at the end stage of these illnesses when palliative care is paramount, and in eating disorders.

Although treatment has come far in the psychological and nutritional approach to eating disorders, few practitioners, academic texts or new therapies focus on the biology of starvation. The development of new treatment follows trendy therapy modalities and new pharmaceutical options, but the medical community remains uninterested in the biology of eating disorders.

The body's adaptation to severe, prolonged malnutrition is profound and powerful. Organ systems will go to great length to survive, and energy conservation is so elemental and complicated that many doctors are stumped by test results in the severely malnourished. Moreover, these adaptations have a psychological component too. Although cognitive function declines in the malnourished, all remaining brainpower focuses on food: obtaining it, savoring it, hoarding it, and of course devouring it.

It's no coincidence that these obsessions are all fundamental symptoms of eating disorders. Ironically, the adaptations which enable the ill to survive may also be the foremost reason people with eating disorders stay trapped in their illness. In other words, many symptoms of eating disorders are the result of starvation, not, as most assume, the other way around.

A look at the basic science of malnutrition helps clear up this confusion. The body suffers three losses without food. First, the sheer lack of calories leaves insufficient energy for the body to function. Second, the body repairs all tissue and organs daily in order to remain healthy, and the lack of variety of nutrients means there are no building blocks to use for repair. Third, the body is constantly dehydrated not because of limited water intake but because of the metabolic changes in starvation. In order to create more energy, the body metabolizes muscle. The chemical pathway to metabolize protein uses water, thereby depleting supply and causing chronic dehydration.

In essence, starvation triggers destructive changes in body function to increase the chance of survival. The three aspects of being malnourished cause widespread damage in all organ systems. The inability to do needed daily repair and the metabolism of tissue for energy leaves the body depleted, only to function at a suboptimal level on backup generators. Forced to survive on very little sustenance, the body hijacks the brain to focus on only what's necessary: food.

The biology of starvation complicates current treatment for eating disorders. When treatment is divided between clinicians, the role of starvation isn't obvious. Therapy working towards the underlying cause for the eating disorder won't address that chronic malnutrition drives the eating disorder thoughts and behaviors. The brain and behaviors have programmed responses to starvation which closely resemble eating disorder symptoms. So for someone chronically starved, these obsessions with food ensure they find and eat any food available. They no longer represent a wish to avoid circumstances or emotions in life; they are a biological response to mortal danger.

The typical result of incorporating the biology of starvation into treatment is twofold. First, it absolves the patient of a large portion of blame. Recognizing that many eating disorder symptoms result from starvation helps the person realize that significant improvement will come from eating, and the goal is to find the environment where that's possible. Second, it eases the pressure to focus on the intensive therapy until starvation is no longer the driving force of the illness.

Furthermore, basic knowledge of the medical factors in these illnesses would help educate families, clinicians and doctors in the true tenacious, destructive nature of eating disorders.